The invention relates to a candle from candle base materials of a variety of kinds.
It is already known to provide candles from a transparent, gel-like candle base material, see for example U.S. Pat. No. 5,879,694 and U.S. Pat. No. 5,578,089. The content of these documents mentioned is hereby incorporated by reference herein as to its full content in the disclosure of the present application, also for the purpose of including features of these documents in claims of the present application. The candle base material previously described, known in particular from the above-mentioned publications, is subsequently identified as candle base material of a first kind.
In addition, a candle base material is also proposed, which in addition to white oil--an oil which in the literature is also known as hydrocarbon oil--and copolymers, also comprises synthetic paraffins, in particular synthetic paraffins of chain length from C18 to C20. In addition, the chain lengths C21 to C25 are for example also possible, in particular cases also shorter chain lengths, C17 and less. In regard to a candle base material of this kind, which has chain lengths of the synthetic paraffin other than C18 to C20, an independent significance is also given. By synthetic paraffins, there is understood such paraffins as are extracted in the Fischer Tropsch process. On the one hand, it is thereby achieved that the candle has a closer relationship to conventional paraffin candles. In addition however, it has surprisingly also been achieved that there is introduced a change from transparent to opaque and also the reverse, the change is reversible, in dependence on a specific temperature, the change temperature. As long as the candle base material or the candle is at a temperature lower than the change temperature, the candle base material or the candle body made from the base material is opaque.
When this temperature is exceeded, a substantially completely clear, see-through candle base material or a like candle appears after a transition state. This may be advantageous in a variety of respects. The candle may also serve as a temperature indicator. On the other hand, when the candle is burning in a cooler environment, a change from opaque to see-through appearing more speedily towards the burning region may be observed. This is also tied in with corresponding light effects. The candle body has a characteristic corresponding to that of a conventional paraffin candle. It is also in particular self-supporting, even with increased addition of the paraffins mentioned. On the other hand, the candle may however also be formed for example in a shell, preferably also in a transparent glass body, by accommodation of the candle base material in the shell. The candle body is penetrated centrally by a wick, as a rule in conventional manner (the wick may be dispensed with in certain circumstances, in which burning away of the candle does not occur, but for example also by means of an associated or even fully incorporated electrical light source, which gives it aesthetic aspects, it may be brought into effect on a permanent basis).
Addition of the copolymers mentioned is also relevant to the structure of the candle body. In particular, various polymers may be used here, for example diblock, triblock, radial block and multi-block copolymers. Especially preferred is the use of a copolymer known as "Kraton G". There is a thermoplastic rubber. In so far as the candle body thus formed is not solid, it has a gel-like structure.
The composition of the candle base material may vary to a great extent within the general teaching of the present application. It is relevant that together a fraction of white oil and the synthetic paraffins mentioned is in the region of approximately 60 to 95%. Depending on the fraction of synthetic paraffins present, the change temperature varies. The higher the fraction of synthetic paraffins, the higher the change temperature. When the fractions are substantially equally important, each thus amounting to approximately 50%, the change temperature is approximately 20.degree.. For a fraction of synthetic paraffins of approximately 90%, the change temperature is approximately 30.degree.. For a fraction of synthetic paraffins of approximately 10%, the change temperature is approximately 6.degree. C.
In addition to the synthetic paraffins mentioned, still further substances may also be added to the candle base material, either individually or in combination. In particular, these may include poly-alpha-olefins, low melting point paraffin fractions, and products derived from natural fats and oils and produced by chemical conversion, such as for example butyl stearate. The poly-alpha-olefins may also be present instead of the synthetic paraffins mentioned. The same also applies to low melting point paraffin fractions and to the products derived from the natural fats and oils mentioned and produced by chemical conversion. These are for example stearic acid butyl ester, lauric acid methyl ester (trade name Edenor MEC 12 98/100), caprylic acid triglyceride (Myritol 312). Along with these synthetic products, natural fats and oils (such as for example coconut oil) may also be used. The previously described candle base material originating from German Patent Application 197 51 351 (and the parallel PCT Application PCT/EP98/07300) mentioned is subsequently also referred to as candle base material of a second kind.
According to the present invention, there is now initially provided a candle consisting of a candle base material of the second kind in one of the embodiments previously described in combination with a candle base material consisting of conventional paraffin, also referred to as wax, i.e. a paraffin derived from crude paraffins. The candle base material derived from conventional paraffin is from now on referred to as a candle base material of a third kind.
The candle base materials of the second and third kind may for example be arranged alternately in layered manner over the height of a candle. They may however also be arranged in spiral manner side by side over the height of the candle. In addition, a mixture or a suspension of the candle base materials is also possible, and this need not be limited to the previously individually discussed candle base materials of the second and third kind, may also be in any desired combination with the candle base material of the first kind.
It is further provided according to the invention that a candle base material of the second kind is combined with a candle base material of the first kind. The candle base material of the first kind is therefore permanently transparent, independent of the temperature. There is in question in the case of this permanently transparent candle base material therefore a gel, the consistency of which is controlled by changing the fraction, the proportion and the kinds of certain polymers, preferably of tri-block, radial block and/or multi-block copolymers, in order to obtain a gel which has the desired rheological properties and thereby yields a candle base material which is solid in itself. While this candle base material of the first kind is fully transparent, it can however be given a coloration, as also further described below in connection also with the further candle base materials, by the use of one or more coloring agents. A tri-block, radial block and/or multi-block copolymer, optionally in conjunction with a di-block copolymer, provides a rigidly cross-linked, stiff gel. The embodiment is achieved by the block copolymers providing a three-dimensional network by physical cross-linkages. The cross-linkages occur in these block copolymers by the formation of sub-microscopic small particles of a particle block, which may also be referred to as domains. The cross-linkage of these permanent domains may also be achieved by factors which influence the cross-link density of the network, including the length of permanent block domains, the length of releasable block domains and the number of cross-linked locations. For example, branched or star-form polymers and other multi-block copolymers have more cross-links than tri-block or di-block polymers. The kind of solution or plastification medium to which the blocks are subjected may also likewise influence these characteristics.
In particular, such a candle base material of the first kind may have from 93 to 98 weight percent of hydrocarbon oil (white oil) and from 7 to 10 weight percent of a copolymer selected from the group of tri-block, radial block and multi-block copolymers, and from 0 to approximately 10 weight percent of a di-block copolymer. The candle base material may also have from 70 to 98 weight percent of hydrocarbon oil (white oil), from 2 to 3 weight percent of a copolymer selected from the group consisting of tri-block, radial block and multi-block copolymers, and from 0 to 10 weight percent of a di-block copolymer.
In a further, optionally also alternative embodiment, this candle base material of the first kind may consist of a clear gel having from 80 to 99 weight percent of hydrocarbon oil (white oil) and from 1 to 20 weight percent of a mixture of at least two different polymer elements, selected from the group which consists of di-block copolymers, tri-block copolymers, radial block copolymers and multi-block copolymers, which composition may have at least one di-block copolymer and at least one tri-block copolymer, and the di-block and tri-block polymers further having portions of styrene monomer units and rubber monomer units.
The at least one di-block copolymer or the at least one tri-block copolymer has from 1 to 99 weight percent of the mixture of at least two different polymers.
The di-block polymers and the tri-block copolymers are derived from thermoplastic rubber.
The candle may also consist of more than two candle base materials, for example the candle base material mentioned of the third kind and/or the candle base material mentioned of the first kind being combined together (the latter if conceptually initially the candle base materials of the second and third kind are under discussion).
In addition, it is in particular also of significance that one or more of the candle base materials mentioned may be given coloration in a candle. In particular, coloration may be provided by a dye, the coloration of which changes in dependence on temperature. Such dyes are referred to here as so-called thermo-dyes, which for example under the trade name "Chromcolor" are distributed by Matsui Shikisu Chemie Limited/Japan. There may also be in question in particular a mixture of micro-encapsulated dyes with paraffin or also polyethylene.
The admixture of a dye, the coloration of which changes in dependence on temperature, thus a thermo-dye, also has significance for a candle which consists of only one of the candle base materials described, which is therefore then given coloration by means of this dye. For example, a candle from a permanently transparent gel may be given coloration by means of a thermo-dye which has a bluish color tone below a specific temperature, indicating coldness, and has a reddish color tone, indicating warmth, above a specific temperature.
By the candle base material of the first kind being thermally reversible, but the candle base material of the second kind enabling also straightforward mixing with dyes and/or scents (in contrast to candle base materials which are based on for example a polyamide resin, which hardens out and the reaction of which can then no longer be made reversible), the mixture is not limited to the dyes described previously, which change their coloration in dependence on temperature.